Question

station 1
understanding the periodic table
if an atom of oxygen has an atomic number of 8, that means-
e. there are 8 protons.
f. there are 8 neutrons.
g. it weighs 8 amu.
h. it is in group 8.

Explanation:

To solve this, we recall the definition of atomic number: the atomic number of an element is equal to the number of protons in its nucleus.

• Option E: Atomic number = number of protons, so oxygen with atomic number 8 has 8 protons. This is correct.
• Option F: Neutrons are calculated as mass number - atomic number, and atomic number doesn't directly give neutrons. So F is wrong.
• Option G: Atomic mass (in amu) is approximately protons + neutrons, not equal to atomic number. So G is wrong.
• Option H: Oxygen is in group 16 (or 6A), not group 8. So H is wrong.

Answer:

E. there are 8 protons.